Prior had just finished striking out his sixth straight Milwaukee Brewer, giving him a 2003 major-league high of 16 strikeouts as he sat down in the dugout after the top of the eighth inning with a 3-2 lead. Baker knew Prior had thrown 126 pitches and told him that looked like enough.

There was a time Prior might have fudged and tried to extend his stay. Not Thursday.

For the second straight day a bullpen collapse cost the Cubs a victory. Joe Borowski blew a save for only the third time in 18 opportunities, surrendering a three-run homer to Geoff Jenkins in the ninth to give the Brewers a 5-3 victory and leave the Cubs with their second straight lost series.

Borowski (1-1) sought out Prior afterward to apologize. But Prior, who admitted he was "gassed" even going out for the eighth inning, didn't need that.

"You're going to save me a lot more times than you're going to give it up," Prior told him with a pat on the back.

It was a devastating end to a great effort, with a Cubs strikeout total second only to Kerry Wood's record-tying 20 against the Houston Astros in 1998.

The defeat was all the more painful because it came the day after the bullpen had squandered a 5-1 lead in a 10-inning 12-6 loss.

The Cubs broke through against Wayne Franklin in the third. Moises Alou looped a single to right-center and Eric Karros slashed a double into the left-field corner to put runners at second and third with no outs. Alex Gonzalez pushed Alou across with a roller to short for a 1-0 lead.

Sammy Sosa stretched that to 3-0 in the fifth with a line drive onto Waveland Avenue for his 10th home run of the season, leaving him two short of Mel Ott's 511 for 16th on baseball's all-time list.

After a one-out double in the second, Prior retired 13 straight before Scott Podsednik's two-out single in the sixth. Keith Ginter followed three pitches later with his second homer of the year to make it 3-2.

The top of the Milwaukee order then did in Borowski in the ninth. Podsednik singled and stole second before a walk to Ginter. Jenkins then lined his 19th home run of the season over the right-field wall.

"I missed my location by about 3 feet," Borowski said. "I made a mistake and he crushed it."

Overshadowed in the Prior masterpiece was the Cubs' failure to take advantage of opportunities. Leadoff man Mark Grudzielanek reached base four of the five times he batted, twice on singles, twice on walks, but scored only on Sosa's home run despite leading off the first with a single and reaching second in the third and seventh.

"We don't want things to slip away from us before the All-Star break," Borowski said. "We want to go into the break with some momentum, and after we come back from there, that's when crunch time comes."